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What is the acceptable minimum cetane rating of a high speed diesel engine?
40
In North America, most states adopt ASTM D975 as their diesel fuel standard and the minimum cetane number is set at 40, with typical values in the 42-45 range. Premium diesel fuel may or may not have higher cetane number depending on the supplier.
What is the best cetane number?
The scale for measuring cetane ranges from 0 to 100, and the higher the number, the better. Modern highway diesel engines tend to require fuel with a cetane number ranging from 45 to 55. Typically, regular no. 2 diesel has a cetane number of 40 to 42, while Cenex® Premium Diesel has a cetane number of 47 to 52.
What is diesel fuel rated by?
cetane
Just as gasoline is rated by its octane, diesel fuel is rated by its cetane, which indicates how easy it is to ignite and how fast it burns. The higher the cetane number, the more volatile the fuel. Most diesel vehicles use fuel with a rating of 40 to 55.
How does cetane number increase in diesel?
Innospec can also provide a nitrogen-free Cetane Number Improver, CI-0808. This additive can be used to increase the Cetane Number of diesel fuels without increasing the fuel nitrogen content. CI-0808 is a blend of Di-tert-butyl peroxide in solvent and is typically used at 0.05% to 0.50% volume.
How do you calculate cetane index?
Cetane index is used as a substitute for the cetane number of diesel fuel. The cetane index is calculated based on the fuel’s density and distillation range (ASTM D86). There are two methods used, ASTM D976 and D4737.
What is the difference between cetane index and cetane number?
The cetane number test uses a standard single cylinder variable compression ratio diesel engine. Cetane index is a calculated value, which is derived from relatively easily measured fuel properties. Thus, cetane index can provide a measure of fuel ignition quality without the need to run the costly cetane number test.
How do I check my cetane rating?
Cetane numbers are measured using a method developed in the 1930s by the Cooperative Fuel Research (CFR) Committee, and later standardized as ASTM D613. The test involves running the fuel in a single cylinder, continuously variable compression ratio CFR Cetane Engine.
How do you increase cetane index?
How to Achieve a Higher Cetane Index
- Hydro-treatment. Treating the fuel with hydrogen during the refinery process is one way of raising the cetane index – but is not without its drawbacks.
- Additives. Substances such as di-tert-butyl peroxide and alkyl nitrates can be used to artificially increase the cetane index.
How cetane number can be improved?
The additives increase the Cetane Number of distillate fuels by improving fuel ignition characteristics in the combustion chamber during the compression stroke. This additive can be used to increase the Cetane Number of diesel fuels without increasing the fuel nitrogen content.
Is it better to use higher cetane number fuel?
There is no benefit to using a higher cetane number fuel than is specified by the engine’s manufacturer. The ASTN Standard Specification for Diesel Fuel Oils (D-975) states. “The cetane number requirements depend on engine design, size, nature of speed and load variations, and on starting and atmospheric conditions.
What is the cetane rating required for US delivery?
US law only requires a minimum cetane rating of 40. Because this value can vary from delivery to delivery, most suppliers will only state the cetane is at least 40. Might be higher or even much higher, but they won’t post it as the next load might just meet the 40 standard.
Can a diesel engine run on low cetane fuel?
Conversely, running a diesel engine on fuel with a lower-than-recommended cetane number can result in rough operation (noise and vibration), low power output, excessive deposits and wear, and hard starting. Cetane Numbers of Various Diesel Fuels Normal modern highway diesel engines run best with a fuel rated between 45 and 55.
What is cetane used for?
Cetane is a colorless, liquid hydrocarbon (a molecule from the alkane series) that ignites easily under compression. For this reason, it was given a base rating of 100 and is used as the standard measure of the performance of compression ignition fuels, such as diesel and biodiesel.